Walking Training Improves Systemic and Local Pathophysiological Processes in Intermittent Claudication.

OBJECTIVE: This study examined the impact of submaximal walking training (WT) on local and systemic nitric oxide (NO) bioavailability, inflammation, and oxidative stress in patients with intermittent claudication (IC). METHODS: The study employed a randomised, controlled, parallel group design and was performed in a single centre. Thirty-two men with IC were randomly allocated to two groups: WT (n = 16, two sessions/week, 15 cycles of two minutes walking at an intensity corresponding to the heart rate obtained at the pain threshold interspersed by two minutes of upright rest) and control (CO, n = 16, two sessions/week, 30 minutes of stretching). NO bioavailability (blood NO and muscle nitric oxide synthase [eNOS]), redox homeostasis (catalase [CAT], superoxide dismutase [SOD], lipid peroxidation [LPO] measured in blood and muscle), and inflammation (interleukin-6 [IL-6], C-reactive protein [CRP], tumour necrosis factor α [TNF-α], intercellular adhesion molecules [ICAM], vascular adhesion molecules [VCAM] measured in blood and muscle) were assessed at baseline and after 12 weeks. RESULTS: WT statistically significantly increased blood NO, muscle eNOS, blood SOD and CAT, and muscle SOD and abolished the increase in circulating and muscle LPO observed in the CO group. WT decreased blood CRP, ICAM, and VCAM and muscle IL-6 and CRP and eliminated the increase in blood TNF-α and muscle TNF-α, ICAM and VCAM observed in the CO group. CONCLUSION: WT at an intensity of pain threshold improved NO bioavailability and decreased systemic and local oxidative stress and inflammation in patients with IC. The proposed WT protocol provides physiological adaptations that may contribute to cardiovascular health in these patients.

Effects of Exercise Mode on Arterial Stiffness in Symptomatic Peripheral Artery Disease Patients: A Randomized Crossover Clinical Trial.

BACKGROUND: Exercise program has been recommended for the treatment of symptomatic peripheral artery disease (PAD) patients. However, whether exercise promotes reduction in arterial stiffness in these patients, who exhibit high arterial stiffness, is poor known. AIM: To analyze the effects of a single session of resistance, walking, and combined exercises on arterial stiffness in symptomatic PAD patients and to describe individual responses and identify clinical predictors of arterial stiffness responses after exercises. METHODS: Twelve patients with symptomatic PAD underwent four experimental sessions in random order: walking exercise (W - 10 bouts of 2-min walking at the speed corresponding to the onset of claudication pain with 2-min interval among sets), resistance exercise (R - 2 sets of 10 reps in eight resistance exercises), combined exercise (CO - 1 set of 10 reps in eight resistance exercises + 5 bouts of 2-min walking with 2-min interval between) and control session (C - resting in exercise room). Ambulatory arterial stiffness index (AASI) was obtained during ambulatory period after each session. Body mass index, ankle brachial index, sex and age also were evaluated. RESULTS: AASI was lower in R compared to other sessions (R - 0.52 ± 0.05; W - 0.59 ± 0.05; CO - 0.64 ± 0.05; C - 0.60 ± 0.05, P < 0.001), with 75% of patients presenting lower AASI after R session. No difference was found between W, CO and C sessions (P> 0.05). Ankle brachial index was negatively correlated with R and W sessions net effect (r = -0.618 and -0.750, respectively; P< 0.05 for both), no correlation was found with CO. CONCLUSION: A single bout of resistance exercise acutely reduces arterial stiffness in symptomatic PAD, while walking and combined exercise did not alter this variable. This response is more likely to occur in individuals with less severe disease.

Cardiovascular Responses during and after Maximal Walking in Men and Women with Symptomatic Peripheral Artery Disease.

BACKGROUND: Walking is recommended for patients with peripheral arterial disease (PAD). It has been shown that patients with PAD present sharper increases in blood pressure (BP) and heart rate (HR) during maximal walking when compared with healthy subjects. Additionally, women with PAD present a worse physiological profile, and it is possible that they may present higher cardiovascular load during and after a bout of maximal walking than men. Thus, the objective of this study was to compare cardiovascular and autonomic responses during and after maximal walking between men and women with PAD and intermittent claudication (IC). METHODS: Forty patients with PAD and IC (20 men and 20 women) underwent, in random order, 2 sessions: control (standing on treadmill) and exercise (maximal treadmill walking test with Gardner's protocol). During the exercise, HR and BP were measured. Before and after the sessions, cardiovascular variables (BP HR, cardiac output, peripheral vascular resistance, and stroke volume) and autonomic modulation (HR and BP variabilities and baroreflex sensitivity) were assessed. In addition, an ambulatory BP monitoring was recorded after each session. RESULTS: Men and women presented similar maximal walking capacity. During the walking test, HR and systolic BP increased similarly in men and women. After the maximal walking, cardiovascular and autonomic responses did not differ between the genders. In addition, postintervention ambulatory BP parameters were also similar in men and women. Therefore, in men and women, maximal walking similarly reduced clinic systolic BP and stroke volume, and increased HR and total power of HR variability during the recovery period. CONCLUSIONS: Men and women with PAD and IC present similar cardiovascular and autonomic responses during and after maximal walking.

Local and Systemic Inflammation and Oxidative Stress After a Single Bout of Maximal Walking in Patients With Symptomatic Peripheral Artery Disease.

OBJECTIVE: The aim of this study was to assess the effects of a single bout of maximal walking on blood and muscle nitric oxide (NO) bioavailability, oxidative stress, and inflammation in symptomatic peripheral artery disease (PAD) patients. METHODS: A total of 35 men with symptomatic PAD performed a graded maximal exercise test on a treadmill (3.2 km/h, 2% increase in grade every 2 minutes). Plasma samples and gastrocnemius muscle biopsies were collected preexercise and postexercise for assessment of NO bioavailability (plasma NO and muscle, endothelial NO synthase), oxidative stress and antioxidant function (lipid peroxidation [LPO], catalase [CAT], and superoxide dismutase), and inflammation (interleukin-6, C-reactive protein, tumor necrosis factor-α, intercellular adhesion molecules, and vascular adhesion molecules). The effects of the walking exercise were assessed using paired t tests or Wilcoxon tests. RESULTS: After maximal walking, plasma NO and LPO were unchanged (P > .05), plasma CAT decreased, and all blood inflammatory markers increased (all P ≤ .05). In the disease-affected skeletal muscle, endothelial NO synthase, CAT, LPO, and all inflammatory markers increased, whereas superoxide dismutase decreased (all P ≤ .05). CONCLUSION: In patients with symptomatic PAD, maximal exercise induces local and systemic impairments, which may play a key role in atherogenesis. Exercise strategies that avoid maximal effort may be important to reduce local and systemic damage and enhance clinical benefits.

Effect of Resistance Training Intensity on Blood Pressure in Older Women.

This study aimed to compare the effects of resistance training performed with low versus moderate loads on systemic resting blood pressure (BP) in older women. A total of 29 women (72.6 ± 5.1 years) were randomized into two groups: low load (LOW, n = 15) and moderate load (MOD, n = 14). An 8-week whole-body resistance training program was carried out 3 days/week (eight exercises, three sets, 10 or 15 repetition maximum). The LOW and MOD groups trained with a relative load of 15 and 10 repetition maximum, respectively. Outcome measures included resting systolic and diastolic BP. After 8 weeks, both groups presented significant changes (p < .05) in systolic BP (LOW = -3.0%; MOD = -4.6%) and mean BP (LOW = -1.9%; MOD = -3.1%). There was no change for diastolic BP in the posttest in both groups. The results suggest that low and moderate loads are equally effective for promoting decreases in resting BP in older women.

Cardiac Autonomic Modulation Is Associated with Arterial Stiffness in Patients with Symptomatic Peripheral Artery Disease.

BACKGROUND: The objective of this study was to analyze the association between cardiac autonomic modulation and arterial stiffness in patients with peripheral artery disease (PAD). METHODS: This cross-sectional study included one hundred fourteen patients with symptomatic PAD (67.5% men; 65 ± 7 years; body mass index: 26.8 ± 4.5 kg/m2). Heart rate variability (HRV) was measured within time (standard deviation of all RR intervals [beat to beat heart interval] [SDNN], root mean square of the successive differences between adjacent normal RR intervals [RMSSD], and the proportion of successive RR intervals that differed by more than 50 msec [pNN50]) and frequency (low frequency [LF] and high frequency [HF]) domains. Arterial stiffness was assessed by carotid-femoral pulse wave velocity (cfPWV). Crude and adjusted linear regression analyses examined the relationship between HRV and cfPWV. RESULTS: Nonsignificant crude associations were identified among cfPWV and RMSSD (P = 0.181), SDNN (P = 0.105), pNN50 (P = 0.087), LF (P = 0.376), HF (P = 0.175), and LF/HF ratio (P = 0.426). After adjustments for age, sex, smoking, body mass index, ankle-brachial index, and use of beta-blockers, significant associations were identified among cfPWV and RMSSD (P = 0.037), SDNN (P = 0.049), and pNN50 (P = 0.049). CONCLUSIONS: Cardiac autonomic modulation was significantly associated with arterial stiffness in patients with PAD after adjustment for confounding factors. This relationship may contribute to the enhanced cardiovascular disease risk for PAD patients and provides a target for strategies to improve patient clinical outcomes.

Factors Associated to Arterial Stiffness in Patients With Symptomatic Peripheral Artery Disease.

BACKGROUND: The aim of this study was to identify the clinical factors associated with arterial stiffness in patients with symptomatic peripheral artery disease. METHODS: In this cross-sectional study, 181 patients (67% men; mean aged 66 ± 9 years) were recruited and had their central arterial stiffness assessed by carotid-femoral pulse wave velocity (cf-PWV). Clinical characteristics are sociodemographic data, body mass index, comorbid conditions, and walking capacity. RESULTS: Multiple linear regression analysis showed that age (b = 0.182, P = 0.032), body mass index (b = 0.254, P = 0.002), and mean blood pressure (b = 0.249, P = 0.021) were positively associated with cf-PWV. CONCLUSIONS: Our results showed that the aging, elevated body mass index, and higher blood pressure are clinical factors associated with increased arterial stiffness in patients with peripheral artery disease.

Reproducibility of Hemodynamic, Cardiac Autonomic Modulation, and Blood Flow Assessments in Patients with Intermittent Claudication.

BACKGROUND: The aim of this study is to identify, in patients with peripheral artery disease and intermittent claudication (IC), the reproducibility of heart rate (HR), blood pressure (BP), rate pressure product, heart rate variability (HRV), and forearm and calf blood flow (BF) and vasodilatory assessments. METHODS: Twenty-nine patients with IC underwent test and retest sessions, 8-12 days apart. During each session, HR, BP, HRV, BF, and vasodilatory responses were measured by electrocardiogram, auscultation, spectral analysis of HRV (low frequency, LFR-R; high frequency, HFR-R), and strain gauge plethysmography (baseline BF, post-occlusion BF, post-occlusion area under the curve). Reproducibility was determined by intra-class correlation coefficient (ICC), typical error, coefficient of variation (CV), and limits of agreement. RESULTS: The ICC for HR and BP was >0.8 with CV <9%. For most HRV measures, ICC was >0.9 while CV was <7%, except for LF/HF (ICC = 0.737, CV = 93.8%). The ICC for forearm and calf baseline BF assessments was >0.9 while CV was <19%; variable ICC and CV for vasodilatory responses were exhibited for calf (0.653-0.770, 35.2-37.7%) and forearm (0.169-0.265, 46.2-55.5%). CONCLUSIONS: In male patients with IC, systemic hemodynamics (HR and BP), cardiac autonomic modulation (LFR-R and HFR-R), and forearm and calf baseline BF assessments exhibited excellent reproducibility, whereas the level of reproducibility for vasodilatory responses were moderate to poor. Assessment reproducibility has highlighted appropriate clinical tools for the regular monitoring of disease/intervention progression in patients with IC.

Association between handgrip strength and vascular function in patients with hypertension.

Background: Increased handgrip strength has been associated with lower cardiovascular and non-cardiovascular mortality in different populations. In patients with hypertension, arterial stiffness relates to cardiovascular mortality. However, whether muscle strength is associated with arterial stiffness in hypertensives is unknown. Thus, the objective of this study was to analyze the association between handgrip strength and arterial stiffness parameters in hypertensive patients. Methods: Seventy-two hypertensive patients completed all evaluations and were included in the analysis. The ambulatory arterial stiffness index (AASI) was obtained based on 24-h ambulatory blood pressure monitoring. Carotid-femoral pulse wave velocity (cfPWV), and reflected wave indicator (AIx and AIx@75) were estimated using applanation tonometry technique, whereas handgrip strength test was performed using a digital dynamometer. Crude and adjusted linear regression models were performed. Results: The crude analysis revealed a negative association between handgrip strength and AASI (b = -0.41, p = 0.002) and AIx (b = -0.49, p < 0.001), and AIx@75 (b = -0.54, p < 0.001) which remained significant after adjustments for age, sex, and body mass index, mean blood pressure, and heart rate only for AASI (b = -0.46, p = 0.028) and AIx@75 (b = -0.24, p- = 0.040). Handgrip strength was not associated with cfPWV (p > 0.05). Conclusion: Handgrip strength is negatively associated with AASI and AIx@75, but not with AIx and cfPWV in hypertensive patients.

Calf Muscle Oxygen Saturation during 6-Minute Walk Test and Its Relationship with Walking Impairment in Symptomatic Peripheral Artery Disease.

BACKGROUND: Impaired microcirculation is associated with poor walking capacity in symptomatic peripheral artery disease (PAD) patients during treadmill test; however, this test does not simulate the efforts of daily walking of these patients. Thus, the aim of the study was to describe the microcirculation responses during a 6-minute walk test (6MWT) and to analyze the relationship between microcirculation indicators and walking impairment in symptomatic PAD patients. METHODS: Thirty-four patients were included (mean age = 67.6 ± 11.2 years). Their clinical characteristics were collected, and they performed a 6MWT, in which the initial claudication distance (ICD) and total walking distance (TWD) were recorded. During and after the 6MWT, calf muscle oxygen saturation (StO2) parameters were monitored continuously to measure microcirculation behavior. The association between calf muscle StO2 parameters and walking impairment were analyzed by Pearson or Spearman correlations. RESULTS: Walking impairment was not associated with any StO2 parameters during exercise. In contrast, after 6MWT, recovery time of StO2 (r = -0.472, P = 0.008) and recovery time to maximal StO2 (r = -0.402, P = 0.019) were negatively correlated with ICD. Furthermore, the distance walked under claudication symptoms (ΔTWD-ICD) was positively correlated with recovery time to maximal StO2 (r = 0.347, P = 0.048). CONCLUSIONS: In symptomatic PAD patients, shorter ICD values during a 6MWT are associated with a delayed recovery in calf muscle StO2 after exercise. Calf muscle StO2 parameters decrease subtly during 6MWT, suggesting that the degree of ischemia in the calf muscle during ground walking, simulating efforts of the daily walking, is relatively low.

Translation and Validation of the Brazilian-Portuguese Short Version of Vascular Quality of Life Questionnaire in Peripheral Artery Disease Patients with Intermittent Claudication Symptoms.

BACKGROUND: The Vascular Quality of Life Questionnaire (VascuQoL-6) was proposed to evaluate specific quality of life of peripheral artery disease (PAD) patients. However, there is no Brazilian-Portuguese version available, blunting its use in Brazilian patients. The objective of the study was to analyze the psychometric properties of a translated Brazilian-Portuguese version of VascuQoL-6 in Brazilian patients with PAD with intermittent claudication symptoms. METHODS: One hundred eleven patients with PAD participated in the study. After translation and retranslation, construct validity was analyzed by identifying correlation between VascuQoL-6 scores, general World Health Organization qualify of life (WHOQOL) score, and subjective and objective functional capacity tests. To determine the reliability, internal consistency and test-retest reliability with at least 7 days interval between 2 questionnaire applications were calculated. RESULTS: Significant correlations between the VascuQoL-6 score and total WHOQOL score (r = 0.44; P < 0.05) were observed. Moreover, we observed negative correlations between the VascuQoL-6 score and 4-meter usual pace (r = -0.33; P < 0.05) and 4-meter fast pace (r = -0.34; P < 0.05) and positive correlation with onset claudication distance (r = 0.39; P < 0.05) and total walking distance (r = 0.29; P ≤ 0.05). Internal consistency was 0.84, whereas the intraclass coefficient correlation was 0.84, with no differences in VascuQoL-6 scores between the 2 applications days. CONCLUSIONS: The Brazilian-Portuguese version of the VascuQoL-6 presents adequate valid and reliability indicators, allowing its use in patients with PAD with intermittent claudication symptoms.

Physical Activity and Heart Rate Variability in Adolescents with Abdominal Obesity.

Physical activity is a protective factor for autonomic dysfunction. However, whether this occurs in adolescents with abdominal obesity is still unclear. Thus, the aim of this study was to analyze the association between physical activity and heart rate variability (HRV) in adolescents with and without abdominal obesity. This cross-sectional study included 1152 boys (age: 17 ± 1 years). HRV measures of time (root mean square of the squared differences between adjacent normal RR intervals-RMSSD and the percentage of adjacent intervals over 50 ms-PNN50) and frequency domains (balance sympathetic-vagal-LF/HF) were evaluated, as well as total physical activity, commuting physical activity, leisure-time physical activity, and abdominal obesity. All physical activity domains were associated with better RMSSD, PNN50, and LF/HF in normal weight adolescents (p < 0.05), whereas in adolescents with abdominal obesity only leisure-time physical activity was associated with better PNN50 (b = 0.174, p = 0.035) independent of age, period of the day, body mass index, and blood pressure. In conclusion, higher leisure-time physical activity, but not total and commuting physical activity levels, was associated with improved HRV in adolescents with abdominal obesity.

Cutoffs of Short-Term Heart Rate Variability Parameters in Brazilian Adolescents Male.

A low heart rate variability (HRV) has been associated with cardiovascular risk factors in adolescents. However, no cut-off points are known for HRV parameters in this age group, making it difficult to use in clinical practice. Thus, the aims of the current study were to establish cutoffs of HRV parameters and to examine their association with cardiovascular risk in Brazilian adolescents male. For this reason, this cross-sectional study included 1152 adolescent boys (16.6 ± 1.2 years old). HRV measures of time (SD of all RR intervals, root mean square of the squared differences between adjacent normal RR intervals, and the percentage of adjacent intervals over 50 ms), frequency domains [low (LF) and high (HF) frequency], and Poincaré plot (SD1, SD2 and SD1/SD2 ratio) were assessed. Cardiovascular risk was assessed by sum of abdominal obesity, high blood pressure, overweight, and low physical activity level. The proposed cutoffs showed moderate to high sensitivity, specificity, and area under curve values (p < 0.05). HRV frequency parameters were statistically superior when compared to time-domain and Poincaré plot parameters. The binary logistic regression analysis indicated that all proposed HRV cutoffs were independently associated with a clustering of cardiovascular risk factors, with greater magnitude of HF and SD1/SD2 ratio (two or more risk factors: OR = 3.59 and 95% CI 1.76-7.34). In conclusion, proposed HRV cutoffs have moderate to high sensitivity in detecting of the cardiovascular risk factor and HRV frequency-domain were better discriminants of cardiovascular risk than time-domain and Poincaré plot parameters.

Association between Sleep Quality and Cardiac Autonomic Modulation in Adolescents: A Cross Sectional Study.

Objective To analyze the impact of sleep quality/duration on cardiac autonomic modulation on physically active adolescents with obesity. Materials and Methods The present cross-sectional study included 1,150 boys with a mean age of 16.6 ± 1.2 years. The assessment of cardiac functions included the frequency domain of heart rate variability (HRV; low frequency - LF; high frequency - HF; and the ratio between these bands -LF/HF -, defined as the sympathovagal balance), and each parameter was categorized as low / high . Physical activity levels and sleep quality/duration were obtained by questionnaires. Abdominal obesity was assessed and defined as waist circumference > 80 th percentile. Results Poor sleep quality resulted in lower HF (odds ratio [OR]: 1.8; 95% confidence interval [95%CI]: 1.01-3.21]) regardless of physical activity and abdominal obesity. Moreover, the study found no association between sleep duration and HRV parameters in adolescents. Conclusion Sleep quality, not sleep duration, reduces parasympathetic cardiac modulation apart from other factors such as physical activity and abdominal obesity in adolescents.

Physiological responses during walking in men and women with intermittent claudication.

BACKGROUND: Miyasato et al. show that peak oxygen consumption, walking economy, anaerobic threshold, and cardiovascular responses (heart rate, blood pressure, and rate pressure product) during walking were similar between men and women with peripheral artery disease and intermittent claudication. There were no differences in the physiological responses to walking between men and women with intermittent claudication. Sex per se is not a factor that demands changes in walking prescription for patients with intermittent claudication. OBJECTIVE: Peak oxygen consumption (VO2peak), anaerobic threshold, walking economy, and cardiovascular responses during walking are used to guide and monitor walking training in patients with peripheral artery disease and intermittent claudication. Women with peripheral artery disease and intermittent claudication present greater impairments than men, and evaluating training markers according to sex for decisions regarding walking prescription in this population is important. This study aimed to compare VO2peak, walking economy, anaerobic threshold, and cardiovascular responses during walking in men and women with peripheral artery disease and intermittent claudication. METHODS: Forty patients (20 men and 20 women with similar baseline characteristics) underwent a cardiopulmonary treadmill test (3.2km/h and 2% increase in slope every 2 minutes until maximal leg pain). The VO2 and rate-pressure product were assessed. Data from men and women were compared using t-tests. RESULTS: There were no significant differences between men and women (VO2peak: 15.0±4.8 versus 13.9±2.9mL∙kg-1∙min-1, p=0.38; walking economy: 9.6±2.7 versus 8.4±1.6mL∙kg-1∙min-1, p=0.09; anaerobic threshold: 10.5±3.2 versus 10.5±2.2mL∙kg-1∙min-1, p=0.98; rate pressure product at 1st stage: 13,465± 2,910 versus 14,445±4,379bpm∙mmHg, p=0.41; and rate pressure product at anaerobic threshold:13,673±3,100 versus 16,390±5,870bpm∙mmHg, p=0.08 and rate pressure product at peak exercise: 21,253±6,141 versus 21,923±7,414bpm∙mmHg, p=0.76, respectively). CONCLUSION: Men and women with peripheral artery disease and similar baseline characteristics presented similar responses to walking, suggesting that decisions regarding walking prescription and monitoring can be made regardless of sex in this specific population.

Walking Training Increases microRNA-126 Expression and Muscle Capillarization in Patients with Peripheral Artery Disease.

Patients with peripheral artery disease (PAD) have reduced muscle capillary density. Walking training (WT) is recommended for PAD patients. The goal of the study was to verify whether WT promotes angiogenesis in PAD-affected muscle and to investigate the possible role of miRNA-126 and the vascular endothelium growth factor (VEGF) angiogenic pathways on this adaptation. Thirty-two men with PAD were randomly allocated to two groups: WT (n = 16, 2 sessions/week) and control (CO, n = 16). Maximal treadmill tests and gastrocnemius biopsies were performed at baseline and after 12 weeks. Histological and molecular analyses were performed by blinded researchers. Maximal walking capacity increased by 65% with WT. WT increased the gastrocnemius capillary-fiber ratio (WT = 109 ± 13 vs. 164 ± 21 and CO = 100 ± 8 vs. 106 ± 6%, p < 0.001). Muscular expression of miRNA-126 and VEGF increased with WT (WT = 101 ± 13 vs. 130 ± 5 and CO = 100 ± 14 vs. 77 ± 20%, p < 0.001; WT = 103 ± 28 vs. 153 ± 59 and CO = 100 ± 36 vs. 84 ± 41%, p = 0.001, respectively), while expression of PI3KR2 decreased (WT = 97 ± 23 vs. 75 ± 21 and CO = 100 ± 29 vs. 105 ± 39%, p = 0.021). WT promoted angiogenesis in the muscle affected by PAD, and miRNA-126 may have a role in this adaptation by inhibiting PI3KR2, enabling the progression of the VEGF signaling pathway.

Sensitivity and Specificity of Cutoff Points of Resting Heart Rate from 6,794 Brazilian Adolescents: A Cross-Sectional Study. / Sensibilidade e Especificidade de Pontos de Corte para Frequência Cardíaca em Repouso de 6.794 Adolescentes Brasileiros: Um Estudo Transversal.

BACKGROUND: Resting heart rate (RHR) may be a useful screening tool for cardiovascular risk. However, RHR cutoff points, an interesting clinical approach, have never been described in young populations. OBJECTIVE: To establish RHR cutoff points in Brazilian adolescents and to analyze whether cutoff points are associated with cardiovascular risk factors. METHODS: The sample was composed of 6,794 adolescents (10 to 19 years old). Blood pressure and RHR were assessed by oscillometric device. Body mass index and waist circumference were also assessed. Receiver operating characteristic curve was adopted to analyze the sensitivity and specificity, and associations of high RHR with cardiovascular risk factors were analyzed by binary logistic regression. A p value < 0.05 was considered statistically significant for all the analyses. RESULTS: Mean RHR values were higher among participants ages 10 to 14 years than 15 to 19 years, for boys (p < 0.001) and girls (< 0.001). The proposed RHR cutoff points for cardiovascular risk factors detection were significant for boys ages 10 to 14 (> 92 bpm) and 15 to 19 years (> 82 bpm), as well as for girls ages 15 to 19 years (> 82 bpm) (p < 0.05 for all), whereas no cutoff point was identified for girls ages 10 to 14 years (p > 0.05). Proposed RHR cutoff points were associated with abdominal obesity, overweight, and high blood pressure in boys in girls. RHR cutoff points were associated with the cluster of cardiovascular risk factors in adolescents ages 15 to 19 years. CONCLUSION: The proposed RHR cutoff points were associated with cardiovascular risk factors in adolescents.

FUNDAMENTO: A frequência cardíaca em repouso (FCR) pode ser uma ferramenta útil de triagem para o risco cardiovascular. Porém, os pontos de corte para FCR nunca foram descritos em populações jovens. OBJETIVO: Estabelecer os pontos de corte para FCR em adolescentes brasileiros e analisar se há associação entre pontos de corte e fatores de risco cardiovascular. MÉTODOS: A amostra foi composta por 6.794 adolescentes (de 10 a 19 anos). A pressão arterial e a FCR foram avaliadas por dispositivo oscilométrico. Também foram avaliados o índice de massa corporal e a circunferência da cintura. Foi adotada a curva ROC para analisar a sensibilidade e especificidade, e as associações de FCR elevada com os fatores de risco cardiovascular foram analisadas por regressão logística binária. Foi considerado estatisticamente significante um valor de p < 0,05 para todas as análises. RESULTADOS: Os valores médios da FCR eram mais altos entre os participantes de 10 a 14 anos do naqueles de 15 a 19 anos, em meninos (p < 0,001) e meninas (< 0,001). Os pontos de corte de FCR propostos para detecção de fatores de risco cardiovascular foram significativos para meninos de 10 a 14 (> 92 bpm) e de 15 a 19 anos (> 82 bpm) e para meninas de 15 a 19 anos (> 82 bpm) (p < 0,05 para todos), enquanto nenhum ponto de corte foi identificado para as meninas de 10 a 14 anos (p > 0,05). Os pontos de corte propostos para a FCR foram associados com obesidade abdominal, sobrepeso e pressão arterial elevada em meninos e meninas. Os pontos de corte da FCR foram associados ao conjunto de fatores de risco cardiovascular em adolescentes de 15 a 19 anos. CONCLUSÕES: Os pontes de corte propostos para a FCR foram associados com os fatores de risco cardiovascular em adolescentes.

Impact of hypertension on arterial stiffness and cardiac autonomic modulation in patients with peripheral artery disease: a cross-sectional study.

OBJECTIVE: To examine the impact of hypertension on cardiovascular health in patients with symptomatic peripheral artery disease and to identify factors associated with uncontrolled hypertension. METHODS: A cross-sectional study including 251 patients with symptomatic peripheral artery disease (63.9% males, mean age 67±10 years). Following hypertension diagnosis, blood pressure was measured to determine control of hypertension. Arterial stiffness (carotid-femoral pulse wave velocity) and cardiac autonomic modulation (sympathovagal balance) were assessed. RESULTS: Hypertension was associated with higher carotid-femoral pulse wave velocity, regardless of sex, age, ankle-brachial index, body mass index, walking capacity, heart rate, or comorbidities (ß=2.59±0.76m/s, b=0.318, p=0.003). Patients with systolic blood pressure ≥120mmHg had higher carotid-femoral pulse wave velocity values than normotensive individuals, and hypertensive patients with systolic blood pressure of ≤119mmHg (normotensive: 7.6±2.4m/s=≤119mmHg: 8.1±2.2m/s 120-129mmHg:9.8±2.6m/s=≥130mmHg: 9.9±2.9m/s, p<0.005). Sympathovagal balance was not associated with hypertension (p>0.05). CONCLUSION: Hypertensive patients with symptomatic peripheral artery disease have increased arterial stiffness. Arterial stiffness is even greater in patients with uncontrolled high blood pressure.

Physiological Responses to Maximal and Submaximal Walking in Patients with Symptomatic Peripheral Artery Disease. / Respostas Fisiológicas à Caminhada Máxima e Submáxima em Pacientes com Doença Arterial Periférica Sintomática.

BACKGROUND: Although maximal and submaximal walking are recommended for patients with peripheral artery disease (PAD), performing these exercises may induce different physiological responses. OBJECTIVES: To compare the acute effects of maximal and submaximal walking on post-exercise cardiovascular function, regulation, and associated pathophysiological processes in patients with symptomatic PAD. METHODS: Thirty male patients underwent 2 sessions: maximal walking (Gardner's protocol) and submaximal walking (15 bouts of 2 minutes of walking separated by 2 minutes of upright rest). In each session, blood pressure (BP), heart rate (HR), cardiac autonomic modulation (HR variability), forearm and calf blood flows (BF), vasodilatory capacity (reactive hyperemia), nitric oxide (NO), oxidative stress (lipid peroxidation), and inflammation (four markers) were measured pre- and post-walking. ANOVAs were employed, and p < 0.05 was considered significant. RESULTS: Systolic and mean BP decreased after the submaximal session, but they increased after the maximal session (interactions, p < 0.001 for both). Diastolic BP did not change after the submaximal session (p > 0.05), and it increased after maximal walking (interaction, p < 0.001). HR, sympathovagal balance, and BF increased similarly after both sessions (moment, p < 0.001, p = 0.04, and p < 0.001, respectively), while vasodilatory capacity, NO, and oxidative stress remained unchanged (p > 0.05). Vascular and intercellular adhesion molecules increased similarly after both maximal and submaximal walking sessions (moment, p = 0.001). CONCLUSIONS: In patients with symptomatic PAD, submaximal, but not maximal walking reduced post-exercise BP, while maximal walking maintained elevated cardiac overload during the recovery period. On the other hand, maximal and submaximal walking sessions similarly increased post-exercise HR, cardiac sympathovagal balance, and inflammation, while they did not change post-exercise NO bioavailability and oxidative stress.

FUNDAMENTO: Embora a caminhada máxima e submáxima sejam recomendadas para pacientes com doença arterial periférica (DAP), a realização desses exercícios pode induzir diferentes respostas fisiológicas. OBJETIVOS: Comparar os efeitos agudos de caminhada máxima e submáxima na função cardiovascular, a regulação e os processos fisiopatológicos associados pós-exercício em pacientes com DAP sintomática. MÉTODOS: Trinta pacientes do sexo masculino foram submetidos a 2 sessões: caminhada máxima (protocolo de Gardner) e caminhada submáxima (15 períodos de 2 minutos de caminhada separados por 2 minutos de repouso ereto). Em cada sessão, foram medidos a pressão arterial (PA), a frequência cardíaca (FC), a modulação autonômica cardíaca (variabilidade da FC), os fluxos sanguíneos (FS) do antebraço e da panturrilha, a capacidade vasodilatadora (hiperemia reativa), o óxido nítrico (ON), o estresse oxidativo (a peroxidação lipídica) e a inflamação (quatro marcadores), pré e pós-caminhada. ANOVAs foram empregadas e p < 0,05 foi considerado significativo. RESULTADOS: A PA sistólica e a PA média diminuíram após a sessão submáxima, mas aumentaram após a sessão máxima (interações, p < 0,001 para ambas). A PA diastólica não foi alterada após a sessão submáxima (p > 0,05), mas aumentou após a caminhada máxima (interação, p < 0,001). A FC, o equilíbrio simpatovagal e os FS aumentaram de forma semelhante após as duas sessões (momento, p < 0,001, p = 0,04 e p < 0,001, respectivamente), enquanto a capacidade vasodilatadora, o ON e o estresse oxidativo permaneceram inalterados (p > 0,05). As moléculas de adesão vascular e intercelular aumentaram de forma semelhante após as sessões de caminhada máxima e submáxima (momento, p = 0,001). CONCLUSÕES: Nos pacientes com a DAP sintomática, a caminhada submáxima, mas não a máxima, reduziu a PA pós-exercício, enquanto a caminhada máxima manteve a sobrecarga cardíaca elevada durante o período de recuperação. Por outro lado, as sessões de caminhada máxima e submáxima aumentaram a FC, o equilíbrio simpatovagal cardíaco e a inflamação pós-exercício de forma semelhante, enquanto não alteraram a biodisponibilidade de ON e o estresse oxidativo pós-exercício.

Reallocating Time From Sedentary Behavior to Physical Activity in Patients With Peripheral Artery Disease: Analyzing the Effects on Walking Capacity Using Compositional Data Analysis.

BACKGROUND: To examine the associations between physical activity (PA) and sedentary behavior (SB) with walking capacity and the effects of reallocating time from SB to PA in patients with symptomatic peripheral artery disease (PAD) using compositional data analysis. METHODS: This cross-sectional study included 178 patients (34% females, mean age = 66 [9] y, body mass index = 27.8 [5.0] kg/m2, and ankle-brachial index = 0.60 [0.18]). Walking capacity was assessed as the total walking distance (TWD) achieved in a 6-minute walk test, while SB, light-intensity PA, and moderate to vigorous-intensity PA (MVPA) were measured by a triaxial accelerometer and conceptualized as a time-use composition. Associations between time reallocation among wake-time behaviors and TWD were determined using compositional isotemporal substitution models. RESULTS: A positive association of MVPA with TWD (relative to remaining behaviors) was found in men (ßilr = 66.9, SE = 21.4, P = .003) and women (ßilr = 56.5, SE = 19.8; P = .005). Reallocating 30 minutes per week from SB to MVPA was associated with higher TWD in men (6.7 m; 95% confidence interval, 2.6-10.9 m) and women (4.5 m; 95% confidence interval, 1.5-7.5 m). CONCLUSIONS: The findings highlight, using a compositional approach, the beneficial and independent association of MVPA with walking capacity in patients with symptomatic PAD, whereas SB and light-intensity PA were not associated.